The present invention relates to voice recognition, and more specifically to improving the performance of a voice recognition apparatus.
A Voice Keypad (VKP) is a device with the ability to recognize keywords uttered by a user and generate corresponding outputs, for example, commands or text-strings, for use by an application device.
One implementation of a VKP is a Bluetooth speakerphone for use with a mobile telephone provided with Bluetooth functionality. In such a device, the VKP speakerphone and mobile telephone are paired. A voice recognition engine on the VKP is implemented to recognize a name uttered by a user with reference to a user-defined name list and output a corresponding telephone number. A dialing function on the mobile telephone then dials the number, and the user is able carry on a conversation through the mobile telephone via the speakerphone.
There are three general classes of voice recognition, namely speaker independent (SI), speaker dependent (SD) and speaker adapted (SA). In the SI system, a voice recognition engine identifies utterances according to universal voice models generated from samples obtained from a large training population. As no individual training by the user is required, such systems are convenient. However, these systems generally have low recognition performance, especially when used by speakers with heavy accents or whose speech patterns otherwise diverge from the training population. On the other hand, SD systems require users to provide samples for every keyword, which can become burdensome and memory intensive for large lists of keywords.
Conventional SA systems achieve limited improvement of recognition performance by adapting voice models according to speech input by an individual speaker. However, it is desirable to achieve a still higher recognition rate for keywords on a VKP. Furthermore, the VKP itself may lack the appropriate resources to achieve improved voice recognition.